1. Technical Field
The present invention relates generally to the removal of sulfur from oil. More particularly, the present invention relates to a system and method for sweetening crude oil. Still more particularly, the present invention relates to a system and method for removal of sulfur from oil via high shear.
2. Background of the Invention
Crude oil is generally associated with significant quantities of hydrogen sulfide and contains various other organic and inorganic sulfur compounds. Natural fossil fuels, such as crude oil and natural gas, that contain a substantial concentration of sulfur compounds, such as hydrogen sulfide, sulfur dioxide, and mercaptans, are referred to as ‘sour.’ Sulfur compounds may evolve from fossil fuels over time and the evolution of these compounds produces significant environmental and safety issues. Emissions of various sulfur compounds, including hydrogen sulfide and sulfur dioxide are regulated. Due to enhanced regulations and restrictions, it is desirable to remove sulfur compounds from crude oil.
There is an ever-increasing shortage of naturally-occurring low sulfur crude oil. With the increasing emphasis on pollution control and the resulting demand for low sulfur content petroleum crude oil, a need for the economical production of sulfur-reduced crude has arisen.
Besides meeting enhanced regulations and restrictions, removal of sulfur from crude oil is desirable for other reasons. Not only does the evolution of sulfur compounds from crude oil produce significant environmental and safety issues, these compounds may also attack metal components of the oil well, as well as pipelines and storage tanks and downstream refinery apparatus. This attack causes corrosion and/or brittleness of the metal components. Additionally, in a refinery, downstream processes may utilize catalysts which are sensitive to the presence of sulfur.
In conventional oil refineries, sulfur is generally removed after the crude oil has been fractionated. Sulfur removal typically comprises utilization of various desulfurization processes, often requiring extreme operating conditions, and incorporation of expensive equipment, often associated with high maintenance costs. Examples of prior art processes for conventional sulfur removal can be found in U.S. Pat. Nos. 1,942,054; 1,954,116; 2,177,343; 2,321,290; 2,322,554; 2,348,543; 2,361,651; 2,481,300; 2,772,211; 3,294,678; 3,402,998; 3,699,037; and 3,850,745, the disclosure of each of which is hereby incorporated herein in its entirety for all purposes not contrary to this disclosure.
Accordingly, there is a need in industry for systems and processes of removing sulfur from crude oil. Desirably, the system and method allow sweetening of crude oil proximal the removal of the oil from the earth. The system and method may also be utilized to enhance the API gravity of the crude oil and/or for removal of other impurities, such as heavy metals, from the crude oil.